/*
 * Copyright 2015 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef SkWebpCodec_DEFINED
#define SkWebpCodec_DEFINED

#include "include/codec/SkEncodedImageFormat.h"
#include "include/codec/SkEncodedOrigin.h"
#include "include/core/SkData.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkTypes.h"
#include "include/private/SkEncodedInfo.h"
#include "include/private/base/SkTemplates.h"
#include "src/codec/SkFrameHolder.h"
#include "src/codec/SkScalingCodec.h"

#include <cstddef>
#include <memory>
#include <vector>

class SkStream;
class SkCodec;
struct SkIRect;
struct SkImageInfo;

extern "C" {
struct WebPDemuxer;
void WebPDemuxDelete(WebPDemuxer *dmux);
}

class SkWebpCodec final : public SkScalingCodec {
public:
    // Assumes IsWebp was called and returned true.
    static std::unique_ptr<SkCodec> MakeFromStream(std::unique_ptr<SkStream>, Result *);
    static bool IsWebp(const void *, size_t);

protected:
    Result onGetPixels(const SkImageInfo &, void *, size_t, const Options &, int *) override;
    SkEncodedImageFormat onGetEncodedFormat() const override
    {
        return SkEncodedImageFormat::kWEBP;
    }

    bool onGetValidSubset(SkIRect * /* desiredSubset */) const override;

    int onGetFrameCount() override;
    bool onGetFrameInfo(int, FrameInfo *) const override;
    int onGetRepetitionCount() override;

    const SkFrameHolder *getFrameHolder() const override
    {
        return &fFrameHolder;
    }

private:
    SkWebpCodec(SkEncodedInfo &&, std::unique_ptr<SkStream>, WebPDemuxer *, sk_sp<SkData>, SkEncodedOrigin);

    SkAutoTCallVProc<WebPDemuxer, WebPDemuxDelete> fDemux;

    // fDemux has a pointer into this data.
    // This should not be freed until the decode is completed.
    sk_sp<SkData> fData;

    class Frame : public SkFrame {
    public:
        Frame(int i, SkEncodedInfo::Alpha alpha) : INHERITED(i), fReportedAlpha(alpha) {}

    protected:
        SkEncodedInfo::Alpha onReportedAlpha() const override
        {
            return fReportedAlpha;
        }

    private:
        const SkEncodedInfo::Alpha fReportedAlpha;

        using INHERITED = SkFrame;
    };

    class FrameHolder : public SkFrameHolder {
    public:
        ~FrameHolder() override {}
        void setScreenSize(int w, int h)
        {
            fScreenWidth = w;
            fScreenHeight = h;
        }
        Frame *appendNewFrame(bool hasAlpha);
        const Frame *frame(int i) const;
        int size() const
        {
            return static_cast<int>(fFrames.size());
        }
        void reserve(int size)
        {
            fFrames.reserve(size);
        }

    protected:
        const SkFrame *onGetFrame(int i) const override;

    private:
        std::vector<Frame> fFrames;
    };

    FrameHolder fFrameHolder;
    // Set to true if WebPDemuxGetFrame fails. This only means
    // that we will cap the frame count to the frames that
    // succeed.
    bool fFailed;

    using INHERITED = SkScalingCodec;
};
#endif // SkWebpCodec_DEFINED
